Compositions comprising graft copolymers of certain aminated alkenyl aromatic monomers on acrylonitrile polymer substrates and method of making

ABSTRACT

Dye-receptive graft polymers comprise a polyester polymer substrate having graft polymerized thereto units of an ethylenically unsaturated monomer which confers dye affinity to the resulting product, e.g. (a) vinyl lactam monomers, particularly vinyl pyrrdidones; (b) sulphonated alkenyl aromatic monomers and alkali metal salts or esters thereof; (c) sulphonated olefines and alkali metal salts or esters thereof; (d) sulphonated esters of acrylic and methacrylic acids and alkali metal salts or esters thereof; (e) sulphonated N-substituted acrylamides and methacrylamides and alkali metal salts or esters thereof; (f) vinyl pyridine and lower alkyl derivatives thereof; (g) amino-substituted alkenyl aromatic monomers; (h) aminoethyl acrylate and methacrylate and N-methyl and -ethyl derivatives thereof; (i) alkenyl aromatic monomers ar-substituted by polyglycol ethers; (j) polyglycol esters of acrylic and methacrylic acids; and (k) N-vinyl-3-morpholinone.  The grafting may be effected by impregnating the polyester with the monomer or a solution or dispersion thereof followed by polymerization of the monomer by means of a free radical catalyst or high energy irradiation, e.g. beta or gamma rays or the radiation from electron beam generators.  The polyester substrate is preferably in shaped form, e.g. a filament. The examples describe the grafting on to a polyethylene terephthalate substrate (cloth) of N-vinyl pyrrolidone, a mixture of N-vinyl pyrrolidone and 2-sulphoethyl methacrylate, 2 -vinyl pyridine, N-vinyl-3-morpholinone and a polyglycol monoacrylate.  The resulting products have good dye-receptivity.  Reference has been directed by the Comptroller to Specification 805,513.

1962 G. w. STANTON ETAL 3, 5

COMPOSITIONS COMPRISING GRAFT COPOLYMERS OF CERTAIN AMINATED ALKENYLAROMATIC MONOMERS ON ACRYLONITRILE POLYMER SUBSTRATES AND METHOD OFMAKING Filed Jan. 29, 1958 Ff/amen 1 0 6/6 ar/l'c/e compr/s/ng a gr0//capo/ymer 0/ ce/fa/n amine/e0 w'ny/ aroma/f0 monomers on anocry/oni/rfle ooZgmer subs/ra/e.

IN V EN TORS. George 14. 5/0/2/0/7 BY redo y 6. fray/0r HTTORNEYSPOLYMER SUBSTRATES AND METHOD OF MAKING George W. Stanton, Walnut Creek,and Teddy G. Traylor,

Concord, (Zaiih, assignors to The Dow Chemical Company, Midland, Mich, acorporation of Delaware Filed Jan. 29, 1958, Ser. No. 711,934 9 Claims.(Cl. 26045.5)

The present invention lies generally in the field of organic chemistryand contributes in particular to the art which pertains to synthetic,fiber-forming high polymers. More particularly, the present inventionhas reference to the provision of certain readily-dyeable graft orblock-type copolymers that are comprised of certain animated vinylaromatic monomers polymerized on acrylonitrile polymer substrates.

Hydrophobic polymeric materials of varying origin are commonly employedin the manufacture of various synthetic shaped articles including films,ribbons, fibers, filaments, yarns, threads and the like and relatedstructures, which hereinafter will be illustrated with particularreference to fibers. iolymers and copolymers of acrylonitrile whichcontain in the polymer molecule at least about 80 percent by weight ofcombined acrylonitrile units may be utilized with great advantage forsuch purposes. Difiiculty is often encountered, however, in suitablydyeing synthetic hydrophobic fibers and the like that have been preparedfrom acrylonitrile polymers, especially those that are comprisedessentially of polyacrylonitrile. This is especially so when it isattempted to obtain relatively deeper shades of coloration in thefinally dyed product.

Various techniques have been evolved for providing acrylonitrile polymercompositions of improved dyeability. These included copolymerizingacrylonitrile with various monomeric materials which are intended tolend an enhanced dye-receptivity to the copolymeric product; blendingpolyacrylonitrile or other acrylonitrile polymers with one or moredye-receptive polymeric materials prior to formation of a fiber productor to the shaped article; and impregnating an already-formedacrylonitrile polymer fiber or other shaped article with a dye-assistingadjuvant or dye-receptive agent, which frequently may be a polymericmaterial.

The practice of such techniques has not always been completelysatisfactory. Neither have the products achieved thereby always provideda completely suitable solution to the problems involved. For example,many of the fiber products which are prepared in accordance with theabove-identified techniques known to the art often have inferiorphysical properties when they are compared with those prepared fromunmodified acrylonitrile polymers, particularly polyacrylonitrile. Also,such products, once they have been prepared, may not be as receptive asmight be desired to a wide range of dyestuffs, due to inherentlimitations in the materials capable of being employed for enhancingdye-receptivity. In addition, especiaily when textile fiber products areinvolved, treatment or modification of the acrylonitrile polymer articlein any of the indicated known ways may not always permit uniformpenetration of the dye throughout the cross-section of the fiber.Frequently, the articles which have been modified according to knownprocedures may exhibit an undesirabie tendency to accept a dyestuff onlyin their peripheral portions. When this phenomenon occurs (which, inconnection with fiber products, is ordinarily re-. ferred to asring-dyeing), fibrillation of the fiber, such as normally results fromits use, exposes the uncolored interior portions. Such behavior, ofcourse, is undesirable atent Q and objectionable in fabrics and othertextile materials constructed with fibers of the acrylonitrile polymers.

It would be advantageous, and it is the chief aim and concern of thepresent invention, to provide acrylonitrile polymers which have beenmodified with certain graft or block copolymerized substituents so as tobe exceptionally dye-receptive while being capable of being fabricatedinto fibers and the like andrelated shaped articles having excellentphysical properties and other desirable characteristics commensuratewith those obtained with the unmodified acrylonitrile polymersubstrates, and of the general order obtainable with unmodifiedpolyacrylonitrile. This would possibilitate the manufacture ofacrylonitrile polymer based fibers and the like articles having thehighly desirable combination of attractive physical characteristics andsubstantial capacity for and acceptance of dyestufi s.

To the attainment of these and related ends, a dyereceptive polymercomposition that is adapted to provide shaped articles having excellentphysical properties and characteristics while being simultaneouslyreceptive of and dyeable to deep and level shades of coloration withmany of a wide variety of dyestuffs is, according to the presentinvention, comprised of a fiber-forming graft or block copolymer whichis comprised or consists essentially of an acrylonitrile polymersubstrate having a minor proportion of substituents graft copolymerizedthereto consisting essentially of polymerized aminated alkenyl aromaticmonomers. Schematically, the compositions may be structurallyrepresented in the following manner:

I l I wherein the interlinked PVCN symbols represent the acrylonitrilepolymer substrate or trunk and the symbols G connected thereto thesubstituent graft copolymer branches of the indicated aminated alkenylaromatic monomer provided thereon.

As is apparent, the graft copolymer substituent that is combined withthe acrylonitrile polymer substrate lends the desired receptivity of andsubstantivity for various dyestuffs to the compositions while theacrylonitrile polymer trunk substrate that is so modified facilitatesand secures the excellent physical properties and characteristics of thevarious shaped articles, including fibers, into which the compositionsmay be fabricated. Advantageously, as mentioned, the acrylonitrilepolymer substrate that is modified by graft copolymerization to providethe compositions of the invention contains in the polymer molecule atleast about percent by weight of combined acrylonitrile. Moreadvantageously, the acrylonitrile polymer substrate consistssubstantially or essentially of polyacrylonitrile.

It is usually beneficial, as has been indicated, for the graft copolymercompositions of the present invention to contain a major proportion ofthe acrylonitrile polymer trunk or substrate that has been modified withthe substituent dye-receptive graft copolymer groups chemically attachedthereto. As a general rule, for example, it is desirable for the graftcopolymer to be comprised of at least about 80 percent by weight of theacrylonitrile polymer substrate. In many instances, it may besatisfactory for the graft copolymer composition to be comprised ofbetween about and percent by weight of the acrylonitrile polymersubstrate, particularly when it is polyacrylonitrile. In thisconnection, however, better dyeability may generally be achieved whenthe grafted aminated alkenyl aromatic copolymer substituents areprepared under such conditions that they have relatively long chainlengths. Thus, it is usually preferable, when identical quantities ofgrafted substituent are involved for relatively fewer, but longer chainlength grafts to be available than to have a greater number ofsubstituents of relatively shorter chain length.

The aminated alkenyl aromatic monomers which are utilized to modify theacrylonitrile polymer substrates so as to provide the graft copolymercompositions of the present invention may be any of those (or theirmixtures) of the structural formula:

CH2=C RQ-O Hz-N G2 (ax) wherein R is selected from the group consistingof hydrogen and methyl; Q is selected from the group consisting ofhydrogen and alkyl radicals containing from 1 to 4 carbon atoms; each Gis independently selected from the group consisting of hydrogen, methyl,and hydroxyethyl (CH CH OH) radicals; X is a halogen (i.e., fluorine,chlorine, bromine or iodine); and n has a whole numerical value fromto 1. As is evident, the ammonium and alkyl ammonium salts of themonomers may be employed. Typical of the monomers of this type that maybe employed advantageously in the practice of the present invention arepara-vinyl benzyl trimethyl ammonium chloride (also known as 4-vinylbenzyl trimethyl ammonium chloride);2-tertiary-butyl-4-vinylbenzyl-N,N-dimethylamine; 2methyl-4-vinyl-benzyl-N- methyl N hydroxyethylamine;4-vinyl-benzyl-N,N-dihydroxyethylamine; 4-vinyl-benzyl-N-methyl-amine;and 4-vinyl-benzyl amine. As is apparent, the aminated vinyl aromaticmonomers may be utilized in the form of the free amines or their halogensalts, particularly the chlorides. Advantageously, the aminated alkenylaromatic monomer that is employed is 4vinyl-benzyl trimethyl ammoniumchloride. If desired, the monomers of the present invention may beutilized in combination or mixture with other varieties of monomers inorder to prepare mixed graft copolymers having specific properties andeffects, particularly with respect to their capability for acceptinggreater numbers of diverse types of dyestuffs. For example, the aminatedalkenyl aromatic monomers provide graft copolymers showing excellentacceptance of direct or acid types of dyestuffs. However, othervarieties of monomers such as those which may provide acidic chemicalcharacteristics in the resulting graft copolymer structure mayfrequently be used with great advantage to enhance the dye-receptivityof the resulting product to basic types of dyestuffs. Such monomers asthe sulfonated vinyl aromatic monomers; the sulfonated olefin monomersand the sulfonated acrylate and methacrylate monomers may frequently beused in beneficial combination with the aminated alkenyl aromaticmonomers contemplated herein.

As mentioned, the graft copolymer compositions of the invention haveremarkably good dye-receptivity, particularly in view of theiracrylonitrile polymer origin. In most cases, for example, thedye-receptivity of the graft copolymer compositions of the presentinvention is improved to such an extent in comparison with unmodifiedacrylonitrile polymers, particularly unmodified polyacrylonitrile, thata color differential of at least about 40 Judd units, as hereinafterillustrated, may readily be obtained between samples of the unmodifiedacrylonitrile polymer substrate and the graft copolymer compositions ofthe present invention, each of which have been dyed at a 4 percentdyeing, according to conventional techniques with such a dyestufi' asCalcodur Pink 2BL. This is a significant advantage when the compositionsare fabricated into shaped article form, especially when they areprepared in a filamentary form suitable for use as a textile material.

The Judd unit is described by D. B. Judd in the American Journal ofPsychology, vol. 53, page 418 (1939). More applicable data appears inSummary on Available Information on Small Color Difference Formulas, byDorothy Nickerson, iuthe American Dye- 4 stuff Reporter, vol. 33, page252, June 5, 1944. Also see Interrelation of Color Specifications, byNiclzerson, in The Paper Trade Journal, vol. 125, page 153, for November6, 1947.

As is well known, Calcodur Pink ZBL is direct type of dye that has aColour Index of 353. It is commercially obtainable under the indicatedtrade-designation. The same dyestutf, which is the sodium salt of3,3-disulphodiphenylurea 4,4 diazobis-Z-amino-S-naphthol- 6-sulfonicacid, is actually available (frequently under other commercialdesignations) from several sources. Calcodur Pink 2BL has the followingstructural formula, as is given on page 88, Section A, Part IV of theColour Index (lst Ed., 1924) published by the (British) Society of Dyersand Colourists:

sogNa NaO S OH More recently, this dyestuff has been designated ColourIndex Direct Red 75.

Besides having excellent physical properties and other desirablecharacteristics, fibers and the like articles comprised of the presentcompositions similarly have the indicated high capacity for beingreadily and satisfactorily dyed to deep and level shades of colorationwith many dyestuffs. For example, fibers of the present compositions maybe easily and successfully dyed according to conventional proceduresusing acid, vat, acetate, direct, naphthol, and sulfur dyes. Suchdyestuffs, in addition to the particular variety mentioned, by way ofdidactic illustration, as Calcocid Alizarine Violet (Colour Index 61710,formerly Colour Index 1080), Amacel Scarlet BS (American PrototypeNumber 244), Sulfanthrene Red 3B (Colour Index Vat Violet 2), NaphtholASMX (Colour Index 35527), Fast Red TRN Salt (Colour Index Azoic Diazo11), and Immedial Bordeaux G (Colour Index unknown or unestablished) mayadvantageously be employed for such purposes.

Other dyestuffs. by way of further illustration, that may be utilizedbenefically on fiber products of the dyereceptive graft copolymercompositions of the invention include such direct cotton dyes asChlorantine Fast Brown CLL (Colour Index unknown or unestablished),Chlorantine Fast Green SBLL (Colour Index Direct Green 27), ChlorantineFast Red 7B (Colour Index Direct Red 81), Pontamine Green GX Conc. 125percent (Colour Index Direct Green 6), Calcomine Black EXN Conc. (ColourIndex Direct Black 38), Niagara Blue NR (Colour Index Direct Blue 151)and Erie Fast Scarlet 4BA (Colour Index Direct Red 24); such acid dyesas Anthraquinone Green GN (Colour Index Acid Green 25), AnthraquinoneBlue AB (Colour Index unknown or unestablished), Sulfonine Brown 2R(Colour Index Acid Orange 51), Sulfonine Yellow 2G (Colour Index AcidYellow 40), Neutracyl Brown RD (Colour Index unknown or unestablished),Xylene Milling Black 213 (Colour Index Acid Black 26A), Xylene MillingBlue FF (Colour Index Acid Blue 61), Xylene Fast Rubing 3GP PAT (ColourIndex Acid Red 57), Calcocid Navy Blue R Conc. (Colour Index Acid BlueCalcocid Fast Blue BL (Colour Index Fast Blue 59), Calcocid Milling Red3R (Colour Index Acid Red 151), Alizarine Levelling Blue 2R (ColourIndex Acid Blue 51), Amacid Azo Yellow G Extra (Colour Index AcidYellow- 63); such mordant-acid dyes as Alizarine Light Green GS (ColourIndex Acid Green 25) and Brilliant Ali-' zarine Sky Blue BS PAT (ColourIndex Acid Blue 129); such vat dyestuffs as Midland Vat Blue R Powder(Colour Index Vat Blue 35), Sulfanthrene Brown G Paste (Colour Index VatBrown Sulfanthrene Black PG Dbl. (Colour Index unknown orunestablished), Sulfanthrene Blue 2B Dbl. paste (Colour Index Vat Blue5), and Sulfanthrene Red 38 paste (Colour Index Vat Vio let 2);Indigosol Green 13 Powder (Colour index Vat Green 1), asoluble vatdyestuff; such acetate dyes as Celliton Fast Brown BRA Extra CF (ColourIndex Dispersed Orange 5), Celliton Fast Rubine BA CF (Colour IndexDispersed Red 13), Artisil Direct Black BKZ (Disperse Dye-Mixture-Colourindex unknown or unestablished), Artisil Direct Navy BR (DisperseDye-Mixture Colour Index unknown or unestablished), Artisil Direct .Red313? and Celanthrene Red 3BN Conc. (Both Colour Index Dispersed Red 15),Celanthrene Pure Blue BRS 400 percent (Colour Index Dispersed Blue 1),Acetamine Orange 3R Cone. (Colour Index unknown or unestablished) andAcetamine Yellow N (Colour Index Dispersed Yellow 32); B-naphthol2-chloro4-nitroaniline, an azoic dye; such sulfur dyes as KatigenBrilliant Blue GGS High Cone. (Colour Index Sulf. Blue 9) and IndoCarbon CLGS (Colour Index Suit. Blue 6); and premetalized dyestuffsincluding Cibalan Yellow GRL (Colour Index Acid Yellow 116) and SupralanBlue NB (Colour Index unknown or unestablished); and the like.

The dyed products, especially textile fiber products are generallylightfast and are well imbued with good resistance to crocking. Inaddition, dyed textile fiber products comprised of the compositions ofthe invention exhibit remarkable washfastness, despite repeated exposureand subjection to washing, laundering and dry cleaning treatments. Ashaped filamentary article prepared from a dye-receptive composition inaccordance with the present invention is schematically illustrated inthe sole figure of the hereto annexed drawing.

The dye-receptive graft copolymers of the present invention may beprepared and provided by impregnating the acrylonitrile polymersubstrate with the monomeric substance then polymerizing the monomer insitu in the acrylonitrile polymer substate. Advantageously, this may beaccomplished when the substrate is in the form of an already shapedarticle, such as a fiber or filamentary structure. Beneficially, thegraft copolymerization of the impregnated monomer may be accomplishedand facilitated with the assistance of a polymerization catalyst orcatalyzing influence which preferentially interacts with the substrateso as to establish or form a grafting site in order to simultaneously orsubsequently initiate the graft copolymerization. As a practical matter,it is generally most desirable to form the graft copolymer compositionsin such manner. Most of the free radical generating chemical catalyst,including peroxide and persulfate catalysts, may be utilized for thedesired graft copolymerization. It may often be exceptionallyadvantageous, how ever, to accomplish the graft copolymerization bysubjecting the monomer-impregnated acrylonitrile polymer substrate to afield of high energy radiation in order to efficiently provide aneifectively attached graft copolymer of the polymerized monomericimpregnant on the hydrophobic acrylonitrile polymer substrate. Thus, thegraft copolymer compositions of the present invention may advantageouslybe provided in accordance with the general procedure that is describedin copending application for United States Letters Patent of George W.Stanton and Teddy G. Traylor having Serial No. 553,701, filed December19, 1955, disclosing a lrocess for Treating Shaped Polymeric Articles toImprove Dyeability.

The monomer maybe intimately impregnated in the acrylonitrile polymersubstrate in any desired manner prior to the graft copolymerization.Thus, the monomer may be directly applied or it may be applied fromdispersion or solution in suitable liquid vehicles until a desiredmonomer content has been obtained. Ordinarily, it is advantageous forthe monomer to be diluted in a solvent or dispersant vehicle so as toprovide a treating bath in which to impregnate the acrylonitrile polymersubstrate with the latter being immersed in the bath for a sufficientperiod of time to attain a desired monomer content in the polymersubstrate which, as has been mentioned, may be in any fabricated orunfabricated form. Unfabricatecl graft copolymer compositions inaccordance with the present invention may be converted to shapedarticles by any desired technique adapted for such purpose withconventional polymers. It is generally desirable and of significantadvantage, however, to impregnate a preformed article, such as a textilefiber of the acrylonitrile polymer (or a cloth or fabric comprisedthereof) with the monomer in order to prepare the graft copolymercompositions of the invention.

In this connection, particularly when preformed fiber structures areinvolved, the article may be in any desired state of formation for theimpregnating and graft copolymerizing modification. Thus fibers andfilms may be treated before orv after any stretch has been impartedthereto. In addition, they may be in various stages of orientation, orin a gel, swollen or dried condition. It is generally advantageous toprepare the compositions of the invention by impregnating the monomerinto the acrylonitrile polymer substrate while the latter is in awater-swollen or hydrated aquagel condition, prior to being finallyconverted to a dried polymer structure. Such aquagels may be obtained byforming the shaped acrylonitrile polymer articles from the acrylonitrilepolymer while it is dissolved inan aqueous saline solution thereof (suchas a 60 percent by weight aqueous zinc chloride solution) as bycoagulation in a suitable aqueous liquid bath capable of having sucheffect. When impregnating baths of the monomer are employed, it isgenerally desirable for them to have a monomer concentration of betweenabout 0.5 and 50 percent by weight and to be prepared as an aqueoussolution of the monomer. This is particularly the case whenacrylonitrile polymers in an aquagel condition are being impregnated.The impregnation of acrylonitrile polymer fibers and related shapedarticles from such a bath may be continued until between about 0.5 and20 percent by weight of monomer, more or less, based on the weight ofthe acrylonitrile polymer substrate is incorporated in the substrate.Obviously, unfabricated polymers may be impregnated in an analogousmanner. Ordinarily, an impregnating bath having a monomer concentrationof between about 5 and 15 percent by weight may advantageously beemployed to impregnate the acrylonitrile polymer substrate with monomerin an amount between about 5 and 15 percent by weight of the polymersubstrate.

The impregnation and succeeding polymerization may, in general, beeffected at temperatures between about 0 C. and about 200 C. for periodsof time ranging up to 4 or more hours. The most suitable conditions ineach instance may vary according to the nature and quantity of thespecific monomeric impregnant involved and the graft copolymerizingtechnique that is utilized. For example, when chemical catalysts areemployed for purposes of forming the graft copolymer, a temperature ofbetween about 50 and C. for a period of time between about 15 and 45minutes may frequently be advana tageously employed for the purpose.Under the influence of high energy radiation, however, it may frequentlybe of greatest advantage to accomplish the graft copolymerization attemperatures between about 20 and 60 C. utilizing relatively low doserates and total dosages of the high energy for the desired purpose.

When the graft copolymer compositions are prepared from preformed oralready shaped acrylonitrile polymer substrates that are successivelyimpregnated with the monomer, which is then graft copolymerized in situin the shaped article, excess monomer, if desired, may be squeezed outor removed in any suitable manner prior to effecting the graftcopolymerization.

The chemical free radical generating catalysts which may be employedwith greatest advantage in the preparation of the graft copolymercompositions of the present invention include hydrogen peroxide, benzoylperoxide, curnene hydroperoxide, ammonium or potassium persulfate andthe like. Such catalysts may be used in conventional quantities toeffect the graft copolymerization. When they are utilized, it is ofgreatest benefit to incorporate them in the impregnating solution of themonomer that is used.

The high energy radiation which may be employed for inducing the graftcopolymerization for the preparation of the graft copolymers of thepresent invention is of the type which provides emitted particles ofphotons having an intrinsic energy of a magnitude which is greater thanthe planetary electron binding energies that occur in the graftcopolymerizing materials. Such high energy radiation is available fromvarious radioactive substances which provide beta or gamma radiation as,for example, radioactive elements including cobalt-60 and cesium-137,nuclear reaction fission products and the like. If it is preferred,however, high energy radiation from such sources as electron beamgenerators, including linear accelerators and resonant transformers,X-ray generators and the like may also be utilized. It is beneficial toemploy the high energy radiation in a field of at least about 40,000roentgens per hour intensity. A roentgen, as is commonly understood, isthe amount of high energy radiation as may be provided in a radiationfield which produces in one cubic centimeter of air at C. and 760millimeters of absolute mercury pressure, such a degree of conductivitythat one electrostatic unit of charge is measured at saturation (whenthe secondary electrons are fully utilized and the wall effect of thechamber is avoided). It is most desirable, incidentally, tograft'copolymerize all or substantially all of the monomeric impregnantto and with the acrylonitrile polymer substrate being modified in orderto provide the compositions of the present invention.

For purposes of specifically illustrating, without intending to therebylimit the invention, the following didactic examples are providedwherein, unless otherwise indicated, all parts and percentages are to betaken by weight.

Example 1 An oriented polyacrylonitrile aquagel fiber that containedabout 1 part of polymer hydrated with about 2 parts of water was soakedfor about 15 minutes in a 10 percent aqueous solution of vinyl benzyltrimethylammonium chloride. After the impregnation, the excessimpregnating solution was squeezed from the fiber so that there wasabout a 3:1 ratio of solution to aquagel respectively. The impregnatedsample was then sealed in a polyethylene bag and irradiated by exposureat room temperature to a high energy, X-ray radiation beam from a Van deGraalf Electrostatic Generator operating under a potential of 2millionelectron volts with a 250 microampere beam current impinging on atungsten target. A total dosage of about 8 mreps. (million roentgenequivalent physicals) at a dose rate of about 23 mreps. per minute wasgiven to the impregnated sample. The irradiated yarn was then rinsedthoroughly with water, dried, heat treated for minutes at 150 C.,scoured and then dyed for one hour at the boil in the conventionalmanner with 4 percent Calcodur Pink 2BL. A deep shade of coloration wasobtained. In contrast, the unmodified yarn could be dyed to only thefaintest degree with the same dyestuff. The graft copolymerized fiberproduct was also dyed well to deep and level shades of coloration withCalcocid Alizarine Violet, an acid type of dyestuff (Color Index 1080);and Amacel Scarlet BS, an acetate type of dyestufi (American PrototypeNo. 244). Its refiectance value (as hereinafter defined) upon a 4percent dyeing in the usual manner with Calcodur Pink 2BL was about 10.

Thedyeing with Calcodu-r Pink 28L was performed at the 4 percent levelaccording to the usual procedure in which the fiber sample wasmaintained for about one hour at the boil in the dyebath which containedthe dyestuff in about an amount equal to about 4 percent of the weightof the fiber. The dyebath also contained sodium sulfate in an amountequal to about 15 percent of the weight of the fiber and had abath-to-fiber weight ratio of 30:1. After being dyed, the fiber wasrinsed in water and dried for about 20 minutes at C. The dye-receptivityof the Calcodur Pink ZBL-dyed fiber (as indicated by its mentionedreflectance value) was evaluated spectrophotometrically by measuring theamount of monochromatic light having a wave length of about 520millimicrons from a standard source that was reflected from the dyedsample. The numerical value obtained was taken along an arbitrarilydesignated scale from 0 to 100. This value represented the relativecomparison of the light that was reflected from a standard white tilereflector that had a reflectance value of 316 by extrapolation from the0 to scale. Lower reflectance values are an indication of betterdye-receptivity in the fiber. For example, a reflectance value of about20 to 25 for acrylonitrile polymer fibers dyed with 4 percent CalcodurPink ZBL is generally considered by those skilled in the art torepresent a degree of dye-receptivity that readily meets or exceeds themost rigorous practical requirements and is ordinarily assured ofreceiving general commercial acceptance and approval. Ordinarily,unmodified polyacrylonitrile fibers of the same type used for thepreparation of the graft copolymerized product generally have areflectance value of about on the same numerical scale. Thus theimprovement in dye-receptivity between the graft copolymerized fiberproduct of the present invention in comparison with unmodifiedacrylonitrile polymers was such that a color differential was about 75Judd units were obtained between the dyed graft copolymer compositionand the unmodified acrylonitrile polymer fiber.

Example 2 The general procedure of Example 1 was repeated with theexception that the aquegel fiber sample was sequentially impregnated inseparate 10 percent aqueous solutions of vinyl benzyl trimethylammoniumchloride and sodium para-styrene sulfonate, respectively, and theimpregnated fiber was subjected to a total dose of about 8 mreps.(million roentgen equivalent physicals) at a dose rate of about 6 mreps.per minute. Deep and level shades of coloration were obtained when thegraft copolymerized fiber product was dyed in the conventional mannerwith 4 percent Calcodur Pink 231 and with 4 percent Sevron Brilliant Red4G, a basic dye formerly known as Basic Red 4G (Colour Index Basic Red14). In contrast the unmodified yarn could be dyed to only the faintestdegree with either of the same dyestuffs.

Results similar to the foregoing may also be obtained when other of thementioned varieties of aminated vinyl aromatic monomers of Formula I areutilized in place.

of those set forth in the above examples and when graft copolymers areprepared with shaped articles or unfabricated forms of acrylonitrilepolymers (including various copolymers) that are treated and irradiatedin other than aquagel forms.

What is claimed is:

1. Dye-receptive graft copolymer composition comprised of (1) anacrylonitrile polymer substrate which is a polymer of polymerizable,acrylonitrile-containing, ethylenically unsaturated monomeric materialthat has in the polymer molecule at least about 80 weight percent ofpolymerized acrylonitrile, said acrylonitrile polymer havwherein R isselected from the group consisting of hydrogen and methyl; Q is selectedfrom the group consisting of hydrogen and alkyl radicals containing from1 to 4 carbon atoms; each G is independently selected from the groupconsisting of hydrogen, methyl, and hydroxyethyl radicals; X is ahalogen and n has a whole number value from O to 1.

2. The composition of claim 1, wherein said acrylonitrile polymer has upto about 20 percent by weight, based on the weight of the composition,of said substituent graft copolymerized units attached thereto.

3. The composition of claim 1, wherein said acrylonitrile polymer hasbetween about 5 and 15 percent by weight, based on the weight of thecomposition, of said substituent graft copolymerized units attachedthereto.

4. The composition of claim 1, wherein said acrylonitrile polymer ispolyacrylonitrile.

5. The composition of claim 1, wherein said substituent graft copolymerunits are comprised of polymerized 4-vinyl-benzyl trimethyl ammoniumchloride.

6. The composition of claim 1, wherein said acrylonitrile polymer ispolyacrylonitrile and wherein said substituent graft copolymerized unitsare present in an amount up to about 20 percent by weight, based on theweight of the composition, and are comprised of polymerized4-vinyl-benzyl trimethyl ammonium chloride.

7. A filamentary shaped article comprised of the composition set forthin claim 6.

8. A filamentary shaped article comprised of the composition set forthin claim 1.

9. Method for the preparation of a dye-receptive graft copolymer whichcomprises polymerizing a minor proportion of a monomer of the formula:

wherein R is selected from the group consisting of hydrogen and methyl;Q is selected from the group consisting of hydrogen and alkyl radicalscontaining from 1 to 4 carbon atoms; each G is independently selectedfrom the group consisting of hydrogen, methyl, and hydroxyethylradicals; X is a halogen and n has a whole number value from 0 to 1, inthe presence of a preformed acrylonitrile polymer which is a polymer ofpolymerizable, acrylonitrile-containing, ethylenically unsaturatedmonomeric material that has in the polymer molecule at least aboutweight percent of polymerized acrylonitrile.

References Cited in the file of this patent UNITED STATES'PATENTS2,691,640 Patterson et a1 Oct. 12, 1954 2,772,310 Morris Nov. '27, 19562,794,793 Coover June 4, 1957 OTHER REFERENCES Bawn, The Chemistry ofHigh Polymers, page 20 published by Interscience Pub., New York, 1948.

1. DYE-RECEPTIVE GRAFT COPOLYMER COMPOLYMER COMPOSITION COMPRISED OF (1)AN ACRYLONITRILE POLYMERSUBSTRATE WHICH IS A POLYMER OF POLYMERIZABLE,ACRYLONITRILE-CONTAINING ETHYLENICALLY UNSATURATED MONOMERIC MATRIALTHAT HAS IN THE POLYEMR MOLECULE AT LEASE ABOUT 80 WEIGHT PERCENT OFPOLYMERIZED ACRYLONITRILE, SAID ACRYLONITRIL POLYMER HAVING CHEMICALLYATTACHED TO CARBON ATOMS IN ITS CHAIN, AS GRAFT COPOLYMERIZEDSUBSTITUENTS THEREON, A MINOR PROPORTION OF UNITS OF (2) A POLYMERIZEDAMINATED ALKENYL AROMATIC MONOMER OF THE FORMULA: